Geometry in music
We do make sense of many things in music spatially (intellectually), albeit it does evoke feelings directly, too. There is tons of research on how musical structure in time (and certain aspects like harmonies, which are basically “overlapping” — see, visual metaphor! — frequencies happening at the same time) is understood spatially. We understand a lot of how this works, and we even know how to apply that knowledge, as every DAW user can tell you.
If there’s an interesting area to learn from how we make sense of complexity, both in feeling and intellectually, then it’s probably music!
Which somewhat brings this full circle to what I mentioned somewhere in respect to the paper The Architecture of Complexity: the fact that we “prefer” spatial (geometric) properties in things is not exclusively a hint that the universe works this way, but equally as much a hint that we’re wired that way. It’s both external and internal to ourselves.
It seems that Alexander found a connection between how we perceive complexity and what the nature of complexity is. This is synthesizing physical, geometric/formal, and cognitive aspects of our existence, which Alexander clearly saw, at least intuitively, while the rest of the world is usually stuck within just one of these modes.